this is something that has been brought up many times. We just had another fellow community member who summed it up pretty well. The only thing I would add is with MLAG it makes it easier to upgrade the cores considering if one switch goes down the other switch picks up the slack. With a stack the entire stack needs to be rebooted in order to apply the image:

Hi Branco, I hope you don't mind that I have edited the title of this topic to more clearly reflect the question.You may want to follow this thread posted earlier today: Two design approaches MLAG vs Stacking

This question comes up from time to time. Here's a couple of similar conversations: